The present invention is directed to a method for fastening a flexible plate on a cylinder of a rotary printing press. The flexible plate has angled suspension legs which are placed in a suspension slit on the cylinder surface. A cylinder groove underlies the slit. Inflatable air hoses and springs are used in conjunction with clamping devices that can be operated in a sequential manner.
A device for fixing a flexible printing plate on the forme cylinder of a rotary printing press having at least one cylinder groove extending in the axial direction is known from DE 43 35 140 C1.
A first, or leading suspension leg, which is beveled at an acute angle, is suspended at an edge of the first groove wall of the cylinder groove of the forme cylinder. A second, or trailing, suspension leg can be placed against the second groove wall, which second groove wall is extending approximately in the radial direction of the forme cylinder, of the cylinder groove. The cylinder groove contains a spindle which is pivotable around its axis. Two leaf springs, each of which is distributed over the width of the printing plate, are fastened on the spindle and can be brought into, or out of contact with the suspension legs in the course of pivoting the spindle.
DE 38 12 137 A1 describes a device for fastening a printing plate, wherein two pivotable fastening elements are seated in a hollow shaft.
EP 0 606 604 B1 discloses a device for the interlocked fastening of a printing plate. In this case, clamping strips are actuated by means of an air hose.
The object of the present invention is directed to providing a method for fastening a flexible plate on a cylinder of a rotary printing press.
In accordance with the present invention, this object is attained by providing the plate receiving cylinder with a plate end receiving suspension slit that overlies a cylinder groove. An inflatable air hose and springs located in the cylinder groove are utilized to shift plate end clamping devices between plate holding and plate release positions. The air hose can be inflated to two different pressure levels. The spring forces exerted by the various springs may also differ. This allows several plates to be released in a sequential manner.
The advantages to be obtained by the present invention consist, in particular, in that a rugged, simply constructed device is created, which can be produced cost-effectively. The device in accordance with the present invention can be displaced without the turning of a spindle in three positions. The device is particularly suited to clamping and releasing of several plates arranged at the circumference of a cylinder. A further advantage of the present invention lies in that in its axial extension it can consist of several short base bodies. It is possible, because of this, to remove the device laterally piece by piece from the cylinder groove, for example for maintenance purposes, without having to dismount the cylinder from the lateral frame. Automatic plate feeding and removal by the use of known devices is possible.